Contribution of HdC Stars to the Galactic Enrichment: The Sr-rich HdC Star HE 1015-2050

Abstract

A fraction of the rare class of Hydrogen-deficient carbon (HdC) stars in our Galaxy are known to exhibit strong features of light neutron-capture elements such as Sr, Y and Zr usually attributed to the weak component of the s-process. Believed to be in a very short-lived evolutionary phase, their ejecta could have significantly contributed to chemical enrichment in the Galaxy. The origin of these stars have long been disputed and poorly understood due to a lack of statistically significant sample. From medium-resolution spectral analyses of a sample of 250 faint high latitude carbon (FHLC) stars, Goswami et al. (2010) have added a new member HE 1015-2050 to this rare class that is found to exhibit anomalously strong features of Sr in its spectrum. Possible scenarios that might have led to the formation of this object are discussed in the light of existing scenarios of HdC star formation.